Log home construction, once a building form born of necessity, is still desirable, not in the least for its romantic, aesthetic appeal. Properly designed and constructed log homes are attractive for their structural longevity and for their warm rustic ambiance.
Improvements have been made in the processes used in milling logs for log home construction, to simplify construction and make the structures more thermally efficient. One such improvement has been to mill the logs for a house to a constant cylindrical shape. This eliminates the time consuming and technically demanding need to arrange and fit tapered logs together. To this end, various milling apparatus has been developed. Such mills turn or shape the logs to a specific determined diameter. It is typical then that the milled logs are moved on to a forming machine where a cutting head is operated to form one or more formed grooves along the log length. The grooves or notches are used to eliminate an age old problem with log construction, what to do about the narrow gap between adjacent logs (the point where one log rests on the log below).
There is a need for a milling arrangement that will produce consistent groove that is centered along a log, considering the fact that logs are not always straight, even after milling. Milling machines typically run along straight tracks, and mill a straight groove along logs that are held on a work support frame. If a straight groove is cut along a crooked log, the log will not set plumb when laid up with the remaining logs in a wall. This seriously detracts from the overall appearance of the structure. However, many present log milling machines have not been adequately designed with a solution to the above problem in mind.
It is often desirable to visually inspect a log to determine the best location for the longitudinal groove. The decision may be made depending on the location of cracks, knots, or bark remaining on the log.
U.S. Pat. No. 4,78,035 is exemplary of a lathe type mill where the problem of providing straight notches is solved by forming the notches while the log is held between the head and tail stock of a lathe. The notches are cut following turning of the log to a prescribed diameter. While this may be fairly effective, it requires that the log be held at its ends and that the lathe remain non functional while the grooving operation takes place. Thus, log production is delayed while the grooves are cut. The log securing apparatus (which in effect is the head and tail stock of the lathe) must be locked to prevent rotation of the log during the groove forming operation.
The above machinery may be functional for short log, lathe milling operations. However, high quality long log production in which logs of various lengths are moved through rotary cutters, cannot make effective use of end engaging head and tail stocks to hold logs for longitudinal groove formation. This is due in part to the long log lengths. Logs are naturally flexible and long logs will bow or sag between lathe centers. Further, if a log has even a slight tendency to bend, head and tail stocks can do little to straighten the bend.
The present invention thus has for an objective, provision of a device that will securely hold a log in place for longitudinal groove forming operations.
Another objective is to provide such a device that will operate independently of a log forming machine, and thereby not interfere or slow operation of the log forming machine.
A further objective is to provide such a device that will permit rotation of an engaged log prior to clamping.
A still further objective is to provide such a device that may straighten a log during the groove forming operation.
Another objective is to provide such a device that is simple in construction and relatively easy to operate.
The above and still further objects and advantages may become apparent from the following description which, taken with the appended drawings and claim, describe and define a preferred mode of carrying out the present invention.